作者:Jérôme Durand、Ennio Zangrando、Carla Carfagna、Barbara Milani
DOI:10.1039/b716656g
日期:——
New atropisomeric bidentate bipyridine-based ligands (3,3â²-(ethylenedioxy)-2,2â²-bipyridine 3; 3,3â²-(propylenedioxy)-2,2â²-bipyridine 4; 3,3â²-(butylenedioxy)-2,2â²-bipyridine 5) containing a bridge between the 3,3â² positions of the aromatic rings have been prepared. Together with the previously reported analogous ligands ((R)-3,3â²-(1-methylethylenedioxy)-2,2â²-bipyridine) 1 and ((S,S)-3,3â²-(1,2-dimethylethylenedioxy)-2,2â²-bipyridine) 2, they were used to synthesize the corresponding bis-chelated dicationic complexes [Pd(NâN)2][PF6]2. Crystal structures and comparison of the data obtained by X-ray analysis on four of these complexes is reported. These palladium compounds were used as precatalysts in the CO/styrene and CO/4-Me-styrene copolymerization reactions, where they showed that small variations in the ligand backbone remarkably affects the productivity of the catalytic system.
新的双齿双吡啶类配体(3,3′-(乙烯醚基)-2,2′-双吡啶 3;3,3′-(丙烯醚基)-2,2′-双吡啶 4;3,3′-(丁烯醚基)-2,2′-双吡啶 5)已被合成,这些配体在芳香环的3,3′位之间有一个桥连接。结合之前报道的类似配体((R)-3,3′-(1-甲基乙烯醚基)-2,2′-双吡啶)1 和 ((S,S)-3,3′-(1,2-二甲基乙烯醚基)-2,2′-双吡啶)2,它们被用于合成相应的双配位阳离子复合物 [Pd(N–N)2][PF6]2。报告了这四个复合物通过X射线分析获得的晶体结构和数据比较。这些钯化合物被用作CO/苯乙烯和CO/4-甲基苯乙烯共聚合反应的前催化剂,显示出配体骨架的小变化显著影响催化体系的产物产量。